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United States Patent |
5,522,881
|
Lentz
|
June 4, 1996
|
Implantable tubular prosthesis having integral cuffs
Abstract
An implantable tubular prosthesis having cuffs adapted to accommodate
stents. The prosthesis includes a hollow tubular conduit with cuffs at
each end. Each of the cuffs has a closed end and a open end to create a
slot for housing the stents. The prosthesis may be an implantable tubular
intraluminal prosthesis for insertion within a body vessel, where the
hollow tubular conduit is radially expandable to buttress the body vessel.
Alternatively, the prosthesis may be an implantable tubular prosthetic
graft for surgical replacement of damaged or diseased existing body
vessels. The tubular prosthesis and stent combination may be radially
expanded so that the stents anchor the prosthesis within the lumen. The
slots which house the stents, prevent contact between the stents and
fluids flowing through the body vessel.
Inventors:
|
Lentz; David J. (Randolph, NJ)
|
Assignee:
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Meadox Medicals, Inc. (Oakland, NJ)
|
Appl. No.:
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267468 |
Filed:
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June 28, 1994 |
Current U.S. Class: |
623/1.13; 606/191; 623/1.29 |
Intern'l Class: |
A61F 002/06; A61F 002/04 |
Field of Search: |
623/1,2,11,12,66
604/93-96
606/191,198
|
References Cited
U.S. Patent Documents
3868956 | Mar., 1975 | Alfidi et al. | 260/24.
|
4140126 | Feb., 1979 | Choudhury | 623/1.
|
4141364 | Feb., 1979 | Schultze | 623/1.
|
4655771 | Apr., 1987 | Wallsten | 623/1.
|
4705517 | Nov., 1987 | Di Pisa, Jr. | 623/1.
|
4728328 | Mar., 1988 | Hughes et al. | 623/1.
|
4787899 | Nov., 1988 | Lazarus | 623/1.
|
5122154 | Jun., 1992 | Rhodes | 623/1.
|
5151105 | Sep., 1992 | Kwan-Gett | 623/1.
|
5163958 | Nov., 1992 | Pinchuk | 623/1.
|
Primary Examiner: Isabella; David
Attorney, Agent or Firm: Hoffmann & Baron
Claims
What is claimed:
1. An implantable prosthesis comprising:
a tubular conduit having an elongate body and opposed open ends, said
conduit being capable of radial diametrical change between a first
diameter and a second diameter;
an elongate cuff formed at one end of said body said cult defining an
open-ended slot between said cuff and said body;
a variable diameter generally annular stent supported by said cuff said
stent being freely insertably and removably positionable within said slot
prior to or after implantation of said body.
2. An implantable prosthesis of claim i wherein said cuff defines a partial
enclosure with said body for enclosing said stent.
3. An implantable prosthesis of claim 1 wherein said cuff has a closed end
and an open end defining a slot for insertable accommodation of said
stent.
4. An implantable prosthesis of claim 1 wherein said tubular conduit
includes a plurality of longitudinal ribs to permit radial contraction
from said first diameter to said second diameter to provide for
intraluminal deployment.
5. An implantable prosthesis of claim 4 wherein said variable diameter
stent is radially collapsible to permit intraluminal deployment thereof.
6. An implantable prosthesis of claim 5 wherein said tubular conduit is
radially expandable from said second diameter to said first diameter after
said intraluminal deployment.
7. An implantable prosthesis of claim 6 wherein said stent is radially
expandable after said intraluminal deployment.
8. An implantable prosthesis of claim 1 wherein said tubular conduit is
formed of a textile fabric.
9. An implantable prosthesis of claim 1 wherein said tubular conduit is
formed from polytetrafluoroethylene.
10. An implantable prosthesis of claim 1 wherein said stent is formed of a
wire mesh.
11. An implantable prosthesis of claim 1 wherein said cuff is integrally
formed with said tubular conduit.
12. An implantable prosthesis of claim 11 wherein one end of said tubular
conduit is folded back upon said body to form said cuff.
13. An implantable prosthesis of claim 12 wherein said one end of said
tubular conduit is folded externally over said body.
14. An implantable prosthesis of claim 12 wherein said other end of said
tubular conduit includes a cuff.
15. An implantable prosthesis of claim 1 wherein said cuff is compliant to
accommodate said stent within a range of different stent sizes.
16. A prosthesis for implantation within a body lumen comprising:
an elongate radially expandable tubular body;
a pair of cuffs, one cuff formed at each end of said body; and
a pair of radially expandable stents one stent resident in each cuff of
said pair of cuffs wherein each of said cuff having an open-ended slot
between said cuff and said body, and said stent being freely insertably
and removably positionable within said slot prior to or after implantation
of said tubular body.
17. A prosthesis of claim 16 wherein said cuffs are elongate members each
having a closed end and an open end for insertion of said stent.
18. A prosthesis of claim 17 wherein said ends of said body are folded back
over to form said cuffs.
19. A prosthesis of claim 18 wherein said cuffs and said tubular body
define slots enclosing said stents.
20. A prosthesis of claim 16 wherein said stent is a generally annular wire
mesh member.
21. A prosthesis of claim 16 wherein said tubular body is formed of a
synthetic fabric.
22. A prosthesis of claim 16 wherein said tubular body is formed of
polytetrafluoroethylene.
Description
FIELD OF THE INVENTION
The present invention relates generally to an implantable tubular
prosthesis. More particularly the present invention relates to an
implantable tubular prosthesis adapted to accommodate stents for
supporting the prosthesis.
BACKGROUND OF THE INVENTION
The implantation of synthetic tubular prostheses to replace or buttress
damaged or diseased vascular vessels or other luminal passageways within
the human body is known. Synthetic tubular prostheses include grafts as
well as endoprosthetic devices.
Tubular prosthesis such as grafts, are typically implanted by surgical
techniques. The surgeon would suture the graft in place in the blood
vessel or other body passageway. Other endoprosthetic devices may be
implanted intraluminally. These devices may be inserted percutaneously by
use of a delivery catheter. Obviously, percutaneous catheter delivery
permits implantation of a prosthesis without the need for major surgical
intervention and the risks inherent therewith. The art therefore is moving
toward the increased use of intraluminal implantation of various
prosthetic devices. It has been found that under certain conditions,
grafts as well as endoprosthetic devices may be implanted by means of a
delivery catheter.
With respect to grafts and other prostheses which may be traditionally
surgically implanted, means other than suturing must be found to secure
these prostheses in place in the body passageway in order to effectively
permit intraluminal implantation. It has been known to employ stents in
combination with grafts and various other prostheses to support and secure
a prosthesis in place in the body passageway after implantation. Stents
are typically radially expandable and/or contractible support members
which are positioned inside of the graft or other tubular prosthesis and
once the tubular prosthesis is properly positioned, the stent would be
expanded to anchor the prosthesis within the body passageway.
However, the use of stents to anchor prostheses is not without problems.
Stents sometimes migrate with the flow of body fluid within a vessel if
undersized or underexpanded. Also, thrombosis or fibrin buildup may occur
within the stent diminishing patency of the intraluminal passageway when
the stent is in direct contact with the blood.
U.S. Pat. No. 5,151,105 discloses an implantable, collapsible tubular
prosthesis, i.e., graft, for surgical implantation within a vascular
organ. The ends of the prosthesis include collapsible circular stents or
annular balloons affixed thereto. The stents expand to seal the ends of
the endo-vascular prosthesis to the inner luminal surface of the blood
vessel into which the prosthesis is implanted. The stents may be sutured
to the interior wall such that they are in direct contact with the body
fluid therein, or may be placed within annular pockets. Because of the
nature of the placement of the stent within the annular pocket, the
insertion must take place before implantation. If problems arise
surrounding the size of the stent, the tubular prosthesis into which the
stent has been sealed must be replaced with a more closely fitting stent.
U.S. Pat. No. 4,728,328 discloses an implantable tubular prosthetic graft
having prosthesis cuffs formed on distal ends of the graft. The cuffs are
formed by folding the edges of the graft back over itself and bonding the
turned back edges to the graft body. These cuffs are then used to suture
the graft to the host vessel. Under certain conditions, however, grafts
require greater support than that afforded by merely suturing through
cuffs positioned at opposing ends of such graft. Also, the need for
suturing would preclude catheter delivery.
Accordingly, there is a need for an implantable tubular prosthesis which
overcomes the aforementioned shortcomings of the prior art and provides a
universal fitting means for cooperatively employing a stent in combination
with the tubular prosthesis.
SUMMARY OF THE INVENTION
In accordance with the present invention, an implantable, tubular
prosthesis is provided that is adapted to be used universally with a
stent. The implantable tubular prosthesis includes a tubular conduit which
is capable of radial diametrical change. The prosthesis also includes at
least one cuff positioned at one end of the conduit. A variable diameter
stent is held or housed by the cuff.
Preferably, the tubular conduit is ribbed longitudinally to permit folding
and insertion into a lumen using a catheter. Alternatively, the tubular
conduit may be crimped longitudinally to permit folding and insertion into
the lumen. The tubular conduit may comprise a braided, knitted or woven
fabric, and may be radially self-expanding to conform to a shape and inner
surface of a lumen into which it is implanted.
The present invention may include an implantable tubular prosthetic graft
or may include an endoprosthetic or intraluminal device.
The present invention also includes a method for repairing a damaged
location of a body vessel that includes the steps of providing a hollow
tubular conduit having cuffs at the ends thereof. A pair of stents is
provided. The tubular conduit is implanted in the body vessel to span the
damaged location. The stents are inserted into the cuffs and the cuffs are
expanded to anchor the conduit in the body vessel on each side of the
damaged location. The stents may be inserted into the cuffs prior to
implantation of the conduit. Alternatively, the stents may be inserted
into the cuffs after implantation.
BRIEF DESCRIPTION OF THE DRAWINGS:
FIG. 1 is a perspective showing of a synthetic tubular prosthesis.
FIGS. 2 and 3 are side elevational and front views respectively of a stent
used in accordance with the present invention.
FIG. 4 shows in longitudinal cross-section the tubular prosthesis of FIG. 1
supporting a pair of stents shown in FIGS. 2 and 3.
FIG. 5 is a side elevational view of the combination shown in FIG. 4.
FIG. 6 is a partial perspective showing of the prosthesis of FIGS. 4 and 5
shown in a partially collapsed condition.
FIG. 7 is a partial sectional showing of the tubular prosthesis of the
present invention implanted within a body vessel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:
The implantable tubular prosthesis having integral cuffs of this invention
may be used as an intraluminal conduit or endoprosthesis for percutaneous
implantation within a diseased or damaged blood vessel or other like
vessel to provide reinforcement and support to the vessel. The implantable
tubular prosthesis may also be used as a vascular graft to replace damaged
or diseased portions of blood vessels or like fluid passageways. The
present invention contemplates catheter delivery of the prosthesis,
however the invention is not limited thereto.
Referring to FIG. 1, an implantable tubular prosthesis 10 is shown.
Prosthesis 10 includes tubular conduit 12 having first and second ends 14
and 16 and a tubular channel 15 therebetween. Tubular prosthesis 10 may be
a textile member formed from braided, knitted or woven synthetic yarns.
Additionally, extruded tubes made from polytetrafluoroethylene (PTFE) and
the like may also be used. Preferably the prosthesis 10 may be formed from
a polymer material such as polypropylene. While the above-described
materials are examples of materials used to form tubular prosthesis 10, it
is of course understood that the present invention may be formed of any
suitable material. As will be described in further detail hereinbelow,
tubular prosthesis 10 may be radially compressed from the structure shown
in FIG. 1 so as to permit insertion into a delivery catheter for
implantation within a body passageway such as a blood vessel, whereupon
the prosthesis is expanded to its original form for secure deployment
therein. Alternatively, tubular prosthesis 10 may be constructed to be of
expandable material so that it is catheter-insertable in its original
state and once positioned within the body passageway may be radially
expanded (or radially self-expanded) for deployment in the vessel.
Referring now to FIGS. 2 and 3, a stent 28 is shown. Stent 28 is generally
an annular member capable of radial expansion between a first diameter and
a second diameter different from the first diameter. Stents such as these
are well known in the art may be formed from materials such as stainless
steel or other metals or alloys, polymeric materials or composites of
polymers and metal and may be shaped in the form of springs,
helically-wound coil springs, wire mesh or other structures and
configurations. Coil springs and the like may also be manufactured from
any expandable heat-sensitive material.
For example, U.S. Pat. No. 4,655,771 discloses an expandable device made
from woven stainless steel wire. Another example of an expandable stent is
disclosed in U.S. Pat. No. 3,868,956. The stent disclosed therein that is
formed with a specific type of metal alloy displaying a memory function.
That is, the alloy with which the stent is formed has the ability when
compressed to recover its initial non-compressed shape upon heating. Such
a stent can be compressed, inserted into and transported within a blood
vessel to a desired position. Once in position, the stent can be heated
for expansion to its original non-compressed state.
In the present illustrative embodiment, a wire mesh stent is shown. The
stent 28 is capable of being radially compressed from the condition shown
in FIGS. 2 and 3 so that it may be intraluminally deployed along with or
subsequent to insertion of tubular prosthesis 10. While a compressible
stent is shown, it is contemplated that a stent which is radially
expandable from an original state may also be employed.
In the preferred embodiment of the present invention tubular prosthesis 10
includes longitudinally extending ribs 18 (FIG. 5) to permit folding or
radial contraction thereof for insertion of the prosthesis 10 into a blood
vessel or other bodily passageway using a catheter, not shown. Although
not shown in FIG. 1, the tubular conduit 12 may also be formed with one or
more longitudinal crimps, creases or the like to enable folding for
insertion of the prosthesis into a blood vessel via a catheter.
Referring now to FIGS. 4 and 5, in accordance with the present invention
tubular prosthesis 10 includes a pair of cuffs 20 and 22 disposed
respectively adjacent ends 14 and 16. The cuffs 20 and 22 may be free
standing cuffs, formed by folding the ends of the tubular conduit 12 back
externally over itself. It is also contemplated that the cuffs may be
formed by turning inwardly the ends of conduit 12. The cuffs 20 and 22 may
also be formed of separate, distinct portions of synthetic material which
may be glued or sutured onto tubular conduit 12. Further, the cuffs may
comprise a material, such as an elastomeric material that is different
than the material comprising the conduit. Cuffs 20 and 22 include inwardly
directed open ends 20a and 22a respectively which are wholly unobstructed
for stent insertion. Open ended slots 24 and 26 are defined between the
external surface of tubular conduit 12 and the internal surface of cuffs
20 and 22. The slots 24 and 26 house one or more stents, such as stent 28,
used by the device to both support and seal the body vessel into which the
tubular prosthesis 10 is inserted. The stents 28 may be used whether the
present invention is used as an implantable prosthetic graft or an
endoprosthesis.
The accommodation of stents 28 within the slots 24 and 26 of tubular
prosthesis 10 helps assure patency of the lumen of a blood vessel or other
body passageway into which the prosthesis 10 is inserted at the exact
place at which support is required. The prosthesis/stent combination
assures a secure anchor of the prosthesis 10 to the inner lumen surface of
the blood vessel due to the radially expansive properties of stent 28.
Stent 28 provides more than means for improved support and anchoring
properties for the invention. Stent 28 also provides a support structure
that is never in direct contact with a body fluid passing through the
intraluminal passageway into which it is installed. Accordingly, fibrin
and thrombotic deposits, common in prior art support structures which are
in direct contact with the blood after implantation, are minimized.
The stent 28 may be inserted and positioned within either or both of cuffs
20 and 22 of prosthesis 10 before implantation. Alternatively, the stent
may be inserted into the prosthesis via catheter after the prosthesis 10
has been implanted. If stents 28 are positioned within cuffs 20 and 22
prior to implantation then the stents may be radially compressed along
with tubular conduit 12 for catheter deployment. However, as above
mentioned, tubular body 12 with cuffs 20 and 22 may be intraluminally
deployed first and then stents 28 may be inserted in a subsequent
procedure. It is still further contemplated that in certain situations,
the stents may be disposed over tubular conduit 12 such as shown in FIG.
5, and then once deployed the stents may be inserted into cuffs 20 and 22.
As mentioned above, implantable tubular intraluminal prosthesis 10 may
include longitudinal ribs 18 which permit prosthesis 10 to be in partially
folded or radially collapsed as shown in FIG. 6. Other techniques for
collapsing prosthesis 10 may also be employed. In the radially collapsed
state, where the tubular conduit 12 as well as cuffs 20 and 22 are
collapsed, the intraluminal prosthesis 10 can negotiate curves or bends of
a blood vessel or other body passageway in which it is implanted and
transported. The device may be inserted percutaneously (in its collapsed
state) by use of a delivery catheter (not shown) and directed to a target
area by any means or method known to those skilled in the art. When
positioned, stent 28 and tubular conduit 12 are then radially expanded to
return to the condition shown in FIGS. 4 and 5. Radial expansion of both
conduit 12 and stents 28 may be accomplished with assistance of, for
example, an expandable catheter balloon. It is also contemplated that the
conduit 12 as well as stents 28 may be constructed to be radially
self-expanding after deployment.
As stents 28 are contained within the slots 24 and 26 outside the lumen of
intraluminal prosthesis 10, the prosthesis has an almost infinitely
variable and adjustable diameter in the ranges between the minimum and
maximum diameter of the tubular conduit 12. Thus, the inner diameter of
the lumen of the vessel in which the device is inserted need not be
exactly known or predetermined.
Referring to FIG. 7, stent 28 is designed to radially expand with the force
sufficient enough to anchor prosthesis 10 within a lumen 32 of a vessel 34
to form a liquid seal therein without placing disruptive force or undue
pressure on the intraluminal walls. If it is determined that a more
appropriately sized stent is necessary for a proper seal after insertion,
the stent can be easily removed and replaced within the cuff by a better
fitting stent without first excising the prosthesis. As the cuffs are
generally flexible and complaint, they may accommodate a range of stent
sizes as may be dictated by the particular application.
Stent 28 is shown clearly supported in slot 24. Because the stent is
enclosed between the prosthesis material of tubular body 12 and cuff
material 20, the stent 28 is never in direct contact with either blood
flowing through lumen 32 or the tissue of the walls of vessel 34. This is
a marked improvement over conventional methods of using stents, normally
attached using hooks or sutures directly to the luminal walls.
As mentioned above, while the preferred embodiment of the present invention
shows an endoprosthesis which is used to reinforce or buttress a body
lumen, it is also contemplated that the present invention may be practiced
with a tubular graft which may be used to replace a missing section of a
body lumen such as a blood vessel.
Thus, while the above embodiments have been disclosed, other and further
manifestations of the present invention will become apparent to those
skilled in the art. It is intended to claim all such changes and
modifications which come within the true scope and spirit of the present
invention.
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